My fuse box is under the boiler. Who can move it and certify

Its not true. Who has told you? Its strange that the electrics get blamed. I can assure you that the fuseboard was there before the boiler. So why would they install a boiler above it if its not allowed? Anyway, regardless of that if you wanted a new CU any qualified electrician can do this. I would not ask your energy supplier they will charge you an outrageous price. Moving a CU is expensive anyway. I would leave it where it is. Or at least get a second opinion. Don't just automatically assume what you have been told is true! There is all sorts of misinformation around and its often busy body types who spread it.

The CU probabley needs changing because its old not just because of its location. Without seeing the set-up you have its difficult to say but having CU under boiler is not good pratice, if boiler springs a leak or during servicing there's a good chance of water mixing with electric! Any Part P registered electrician can replace the CU, post a job on My builder to find good electrician for advice and a price. Expect to pay for a days labour and around £150 for CU. I would not recommend using energy supplier, most of the call handling staff won't understand what you need and if you do get them to place a call it can be very expensive.

Technically it actually all comes down to the distance of the gas installation pipe work and the exact position of the board, if there is no kind of insulating enclosure or barrier providing legitimate separation between the separate services (min 150mm between a board/consumer unit and a gas meter and live pipe work. Also, minimum of 25mm clearance between either the electricity supply or distribution cables!) Instead of spending out on a new board as this might not always be feasible, insulating and sheathing all pipe work with an electric insulation with a minimum rating of 230v is acceptable. Hope you might find this helpful......

Without the aid of pics it’s hard to give an accurate assessment. Where is the supply authority’s cut out and meter? Is it on the other side of the wall? The meter tails shouldn’t be more than 3 meters in length unless there’s additional protection in place. You may be restricted in relocating the CU depending on the location of the SA equipment. Perhaps that’s why you’ve been told in needs to be your energy supplier.